Battery Cell, Battery, and Power Consuming Device

This application is a continuation of International Application No. PCT/CN2023/126107, filed on Oct. 24, 2023, which claims priority to Chinese Patent Application CN202310279916.4, entitled “BATTERY CELL, BATTERY, AND POWER CONSUMING DEVICE” and filed on Mar. 21, 2023, which are incorporated herein by reference in their entirety.

This application relates to the field of battery technologies, and in particular, to a battery cell, a battery, and a power consuming device.

Energy conservation and emission reduction are keys to sustainable development of the automobile industry, and due to advantages of energy conservation and environmental protection, electric vehicles become an important part of the sustainable development of the automobile industry. For the electric vehicles, the battery technology is also an important factor related to development of the electric vehicles.

During manufacturing of a battery, the reliability of the battery is a non-negligible issue. Therefore, how to improve the reliability of the battery is a technical problem to be urgently resolved in the battery technology.

An objective of this application is to provide a battery cell, a battery, and a power consuming device. The battery cell has high reliability.

This application is implemented through the following technical solutions:

According to a first aspect, this application provides a battery cell, including a housing, an electrode terminal, an electrode assembly, an insulating member, and a liquid absorbing member, where the housing includes a first wall; the electrode terminal is arranged on the first wall; the electrode assembly includes a body and a tab extending out from the body, and the tab is electrically connected to the electrode terminal; the insulating member is arranged between the first wall and the electrode assembly, and the insulating member is configured to isolate the first wall from the electrode assembly; and the liquid absorbing member is located between the body and the insulating member, and the liquid absorbing member is configured to absorb an electrolyte solution.

According to the battery cell provided in this embodiment of this application, in a use scenario in which the body of the electrode assembly is arranged on the insulating member, the liquid absorbing member is located between the body and the insulating member, and the liquid absorbing member can absorb the electrolyte solution located between the insulating member and the body, to reduce a free electrolyte solution on a side of the insulating member facing the body, so that a possibility that the electrolyte solution participates in an electrochemical reaction between metal particles or separated active substances and the housing is reduced, and a risk of corrosion and liquid leakage of the housing is reduced. Therefore, the battery cell has high reliability.

According to some embodiments of this application, the housing includes a shell and an end cap, the shell has an opening, the end cap closes the opening, the end cap is connected to the shell to form a connection portion, the end cap is the first wall, and along a thickness direction of the end cap, a projection of the liquid absorbing member on the end cap does not overlap with the connection portion.

In the foregoing solution, the end cap is the first wall, the projection of the liquid absorbing member on the end cap does not overlap with the connection portion, so that after the liquid absorbing member absorbs the electrolyte solution, a possibility that the electrolyte solution remains at the connection portion is reduced, and a risk of corrosion and liquid leakage of the connection portion can be reduced.

According to some embodiments of this application, the battery cell further includes a pressure relief mechanism, the pressure relief mechanism is arranged on the first wall, and along a thickness direction of the first wall, a projection of the liquid absorbing member on the first wall does not overlap with the pressure relief mechanism.

In the foregoing solution, the pressure relief mechanism is arranged on the first wall, and the projection of the liquid absorbing member on the first wall does not overlap with the pressure relief mechanism, so that the liquid absorbing member absorbs a free electrolyte solution, accumulation of the electrolyte solution at the pressure relief mechanism is reduced, and a risk of corrosion and liquid leakage of the pressure relief mechanism is reduced.

According to some embodiments of this application, the battery cell further includes an adapting member, the adapting member is arranged on a side of the insulating member facing the electrode assembly, the adapting member connects the electrode terminal to the tab, and along the thickness direction of the first wall, a projection of the adapting member on the first wall at least partially overlaps with the projection of the liquid absorbing member on the first wall.

In the foregoing solution, the projection of the adapting member on the first wall at least partially overlaps with the projection of the liquid absorbing member on the first wall, so that the liquid absorbing member absorbs the electrolyte solution to the vicinity of the adapting member, and the electrolyte solution is in contact with the tab, transported to a separator through the tab, and absorbed and stored by the separator.

According to some embodiments of this application, along the thickness direction of the first wall, a gap exists between the adapting member and the insulating member, and at least a part of the liquid absorbing member is located in the gap.

In the foregoing solution, at least a part of the liquid absorbing member is located in the gap, and expansion and deformation of the liquid absorbing member after absorbing the electrolyte solution are limited through the adapting member, so that the electrolyte solution absorbed by the liquid absorbing member is squeezed out, and the squeezed electrolyte solution can be transported to the separator along the tab to be stored by the separator.

According to some embodiments of this application, the tab is connected to a side of the adapting member facing away from the insulating member.

In the foregoing solution, the tab is connected to the side of the adapting member facing away from the insulating member, so that the adapting member and the insulating member are assembled, and the tab is connected to the adapting member.

According to some embodiments of this application, along the thickness direction of the first wall, the projection of the liquid absorbing member on the first wall at least partially overlaps with a projection of the tab on the first wall.

In the foregoing solution, the projection of the liquid absorbing member on the first wall at least partially overlaps with the projection of the tab on the first wall, so that the electrolyte solution absorbed by the liquid absorbing member is transported to the separator along the tab to be stored by the separator. When the tab is connected to a side of the adapting member facing the insulating member, the tab is close to the liquid absorbing member or is in contact with the liquid absorbing member, and the electrolyte solution absorbed by the liquid absorbing member is easily in contact with the tab, so that the electrolyte solution is easily transported to the separator through the tab. When the tab is connected to the side of the adapting member facing away from the insulating member, expansion of the liquid absorbing member after absorbing the electrolyte solution is limited by the adapting member, the electrolyte solution absorbed by the liquid absorbing member is squeezed out, and the squeezed electrolyte solution easily accumulates on the side of the adapting member facing away from the insulating member, so that the electrolyte solution is easily in contact with the tab and is transported to the separator through the tab.

According to some embodiments of this application, the liquid absorbing member includes a first portion and a second portion, the first portion is located in the gap, and the second portion is connected to the first portion and protrudes out of an edge of the adapting member.

In the foregoing solution, the second portion protrudes out of the edge of the adapting member, after expansion of the first portion after absorbing the electrolyte solution is limited by the adapting member, the electrolyte solution can be squeezed out, and after the second portion is expanded after absorbing the electrolyte solution, the electrolyte solution at the liquid absorbing member is easily in contact with the tab and is transported to the separator through the tab.

According to some embodiments of this application, the second portion is in contact with the tab.

In the foregoing solution, the second portion is in contact with the tab, so that the electrolyte solution is transported to the separator through the tab to be stored by the separator.

According to some embodiments of this application, along the thickness direction of the first wall, a size of the gap is H, and H meets: 0.2 mm≤H≤1 mm.

In the foregoing solution, through arrangement of the gap, the liquid absorbing member can be accommodated, and space occupation can be reduced.

According to some embodiments of this application, 0.4 mm≤H≤0.6 mm.

In the foregoing solution, compared with a case that 0.2 mm≤H, when 0.4 mm≤H, the liquid absorbing member is thick; and compared with a case that H≤1 mm, when H≤0.6 mm, the liquid absorbing member occupies a limited space.

According to some embodiments of this application, the battery cell further includes a support member, the support member is arranged on a side of the insulating member facing the electrode assembly, the support member is located between the insulating member and the body, the tab is bent around the support member, the support member is configured to prevent the body from moving along a direction facing the first wall, and the liquid absorbing member is arranged between the support member and the insulating member.

In the foregoing solution, the support member is located between the insulating member and the body, and the tab is bent around the support member, so that the support member can facilitate bending of the tab and can be supported between the insulating member and the body, to position the body, thereby reducing a possibility that the tab is driven to move by movement of the body and reducing a risk that a joint between the tab and another component is damaged.

According to some embodiments of this application, the battery cell further includes an adapting member, the adapting member is arranged between the insulating member and the support member, and the adapting member connects the electrode terminal to the tab.

In the foregoing solution, the adapting member is arranged between the insulating member and the support member, to implement an electrical connection between the electrode terminal and the tab.

According to some embodiments of this application, along the thickness direction of the first wall, the projection of the adapting member on the first wall at least partially overlaps with the projection of the liquid absorbing member on the first wall.

In the foregoing solution, when the liquid absorbing member is located between the adapting member and the insulating member, the adapting member and the insulating member can limit an expansion and deformation amount of the liquid absorbing member after absorbing the electrolyte solution, so that the electrolyte solution is guided by the liquid absorbing member to the vicinity of the adapting member, and the electrolyte solution is in contact with the tab, transported to the separator through the tab, and absorbed and stored by the separator. When the liquid absorbing member is located between the adapting member and the support member, the liquid absorbing member may be close to the tab, so that the liquid absorbing member can guide the electrolyte solution to the vicinity of the tab, and the electrolyte solution is in contact with the tab, transported to the separator through the tab, and absorbed and stored by the separator.

According to some embodiments of this application, the liquid absorbing member is made of an insulating porous material.

In the foregoing solution, the liquid absorbing member has an insulation function to reduce a risk of short circuit caused by contact between components inside the battery cell, and the porous material has a good adsorption effect, so that the liquid absorbing member can absorb more electrolyte solutions.

According to some embodiments of this application, the tab includes a plurality of stacked sub-tabs.

In the foregoing solution, the tab includes a plurality of sub-tabs, a gap exists between every two adjacent sub-tabs, and after the electrolyte solution comes into contact with the tab, under capillary action, the electrolyte solution moves toward the separator along the sub-tabs.

According to some embodiments of this application, an initial volume of the liquid absorbing member is V, and after the liquid absorbing member absorbs the electrolyte solution and is saturated, a volume of the liquid absorbing member is V, and Vand Vmeet: 5≤V/V≤10.

In the foregoing solution, the liquid absorbing member has a good saturation absorption capacity, so that a liquid absorbing effect is good; if V/Vis small (for example, less than 5), the liquid absorbing member has a small saturation absorption capacity, and a liquid absorbing effect is not good; and if V/Vis large (for example, greater than 10), when the liquid absorbing member is arranged between the adapting member and the insulating member and the tab is connected to the side of the adapting member facing away from the insulating member, volume expansion of the liquid absorbing member is excessively large, leading to an excessively large forced deformation amount of the tab.

According to some embodiments of this application, 7≤V/V≤9.

In the foregoing solution, compared with a case that 5≤V/V, when 7≤V/V, the saturation absorption capacity of the liquid absorbing member is large, and the liquid absorbing effect is good; and compared with a case that V/V≤10, when V/V≤9, the volume expansion of the liquid absorbing member is small.

According to a second aspect, an embodiment of this application provides a battery, including the battery cell according to any one of the foregoing embodiments.

According to a third aspect, an embodiment of this application provides a power consuming device, including the battery cell according to any one of the foregoing embodiments or the battery, where the battery cell is configured to provide electric energy.

Additional aspects and advantages of this application are partially given in the following description, and partially become apparent from the following description or may be learned from practices of this application.

In the accompanying drawings, the accompanying drawings are not drawn in an actual proportion.

—Vehicle;—Battery;—Box;—First sub-box;—Second sub-box;—Battery cell;—Housing;—Shell;—End cap;—First wall;—Electrode terminal;—Electrode assembly;—Body;—Tab;—Insulating member;—Liquid absorbing member;—First portion;—Second portion;—Adapting member;—First connection segment;—Second connection segment;—Pressure relief mechanism;—Support member;—Support portion;—Separation portion; Q—Gap;—Controller; and—Motor.

The following describes implementations of this application with reference to the accompanying drawings and embodiments. The detailed description of the following embodiments and the accompanying drawings are used for exemplarily describing the principle of this application, but cannot be used for limiting a scope of this application. That is, this application is not limited to the described embodiments.

Unless otherwise defined, meanings of all technical and scientific terms used in this application are the same as those usually understood by a person skilled in the art to which this application belongs. In this application, terms used in the specification of this application are only intended to describe specific embodiments, and are not intended to limit this application. In the specification, claims, and accompanying drawings of this application, the terms “include”, “have”, and any other variants are intended to cover non-exclusive inclusion.

In the specification, claims, and accompanying drawings of this application, the terms “first”, “second”, and the like are intended to distinguish between different objects but do not indicate a particular sequence or primary-secondary relationship.